Still picture projection machine



May 15, 1951 A. J. BRADFORD 2,553,075

STILL PICTURE PROJECTION MACHINE May 15, 1951 A. J. BRADFORD STILL PCTURE PROJECTION MACHINE Filed sept. ze, 194s 6 Sheets-Sheet 2 A'. J. BRADFORD STILL PICTURE PROJECTION MACHINE May 15, 1951 6 Sheets-Sheet 5 7. E' in.

Filed Sept. 28, 1946 n lu May 15, 1951 A. J. BRADFORD STILL PICTURE PROJECTION MACHINE 6 Sheets-Sheet 4 Filed Sept. 28, .1946

May 15 l951 A. J. BRADFORD 2,553,075 l STILL PCTURE PROJECTION MACHINE Filed Sept. 28, 1946 J 6 Sheets-Sheet 5 f l l 136 f 6 Egg' j@ l 1.215 /af /47 l "92 43 a /o/ 1% fao /az l Lss 1 :Q L J /m /0/ /02 ,y l /22 7 /12 a fas /2/ flo fra /4 6 05107 2 9 [/4 [[3 /06 May15, 1951 A. J. BRADFORD 2,553,075

STILL PICTURE PROJECTION MACHINE Filed Sept. 28, 1946 6 Sheets-Sheet 6 IW U guide.

Patented May 1.5, i951` UNITED STATS FTENT OFFICE mesne assignments, to

Ampro Corporation,

Chicago, Ill., a corporation of Illinois Application September 28, 1946, Serial No. 700,049

4 Claims. l

This invention relates to projection machines for projection of pictures and the like from slides An object of this invention is to provide an improved projection machine wherein mechanism is provided between the source of light and the adjustable focusing lens for inserting film in one transverse plane between the source of Ylight and the adjustable focusing lens and for inserting slides in another transverse plane between the source of light and the adjustable focusing lens. By reason of this two-plane mechanism, slides or films may be readily projected from the same machine without requiring disassembly and reassembly of the machine. v

In accordance with this invention, the mechanism' may include a film guide having a light transmitting aperture for guiding the nlm in one transverse plane and it may include a slide shifter support for receiving and supporting the slide shifter in the other plane. Means may also `be provided for moving the film guide laterally out of the light path when a slide is projected and means may further be provided for laterally closing the slide shifter support when a film is to be projected.

Another object of this invention is to provide an improved mechanism for moving the film along a film guide. In this connection, a sprocket is provided at one end of the film guide for drawing the iilm along the guide and a sprocket is provided at the other end of the lilm guide for normally feeding the nlm to the lm The feeding sprocket is provided with a friction brake to hold back and apply tension to the iilm on the guide as the film is being moved by the other sprocket. The feeding sprocket may also be rotated to provide reverse feed of the film.

'f Further objects of this invention reside in the details of construction of the component parts of the projection machine and the cooperative relation therebetween.

Other objects and advantages will become apparent to those skilled in the art upon reference to the accompanying specification, claims, and drawings in which:

Figure 1 is a side elevational view of the projection machine;

Iigurs-z 2 is a vertical sectional view through lthe projection machine of Figure 1;

Figure 3 is a side elevational view of the light .concentrating box;

Figure 4 vis a front elevational view of Fig- Ure. 3;.

taken substantially along the line Figure 5 is a sectional view taken substantially along the line 5 5 of Figure 3;

Figure 6 is a perspective View of one of the plates for supporting the filters and concentrating lenses;

Figure '7 is a front elevational view of the projection machine with the slide shifter in place;

Figure 8 is a perspective view of a shield for .covering the side openings of the slide shifter support;

Figure 9 is a partial side elevational View similar to Figure 1, but illustrating the slide shifter in place;

Figure 10 is a vertical front sectional view Ill- I0 of Figure 1;

Figure 11 is a partial perspective vie-w of a part of the mechanism shown in the upper portionv of Figure 10;

Figure 12 is a partial perspective view showing a part of the mechanism of the lower portion of Figure 10;

Figure 13 is an elevational view of the lower knob of Figure 10 looking from the right;

Figure 14 is an enlarged partial sectional view of the film guiding mechanism showing the pivoted arms in free position; y

Figure 15 is a view similar to Figure 14, but showing the pivoted arms in guiding position;

Figure 16 is a partial perspective View of a portion of the container of Figure 14;

Figure 17 is a perspective view of the lower pivoted lever of Figure 14.

The projection vmachine is generally designated at II'I in Figures 1, 2, and '7 and it includes a base I I provided with supporting feet I2. The base II is also provided with internal pins I3 received in openings in the side walls of a lamp box I 4. The lamp box I4 is substantially rectangular in cross section and is open at the top and bottom, as sho-wn in Figure 2. Across the bottom of the lamp box is suitably secured a strip I5 for carrying a lamp socket I6 which in turn receives a lamp I1 having an opaque top I8. Electrical energy is supplied to the lamp socket I5 and hence to the lamp I'I by a cord I9 provided with a suitable plug 20. A switch ZI makes and breaks the electrical connections for turning on and oi the lamp I1.

A wheel 23 carried by a screw threaded shaft 24 is provided with a bearing extension 25 rotating in a bearing sleeve 26 carried by the base II. The screw threaded shaft 24 extends upwardly through an opening 21 inthe strip I5 and the screw threadedlyengages a nut 28 carried by a leaf spring 29 which in turn is secured to the lamp box is by a screw 33. By rotating the wheel 23 in one direction, the nut 2t is dr wn downwardly to cause clockwise movement of the lamp box lil about the pivots i3, thereby tilting the projection machine in one direction. Upon reverse rotation ofthe wheel-23, the nut 28 is driven upwardly whereby the lamp box lli is moved in a counter-clockwise direction about the pivots I3 to tilt the projection machine in the opposite direction. Alignment of the projection machine is thus provided.

The lamp box Iii is internally provided in the back thereof with a sheet S2 of insulating material to protect the box from the heat given off by the lamp il. suitably secured, as by Welding, to the upper end of the lamp box Irl is a flange 33 which receives a latticed cover 3G. The cover 35i is open, but is provided with a crisscross lattice formed from strips 35. Some of the lattice strips, such as 3e, extend downwardly and are secured, as by welding, to a light-concentrating box 3l for supporting the latter. The light-concentrating box 3T encompasses the lamp il and is provided on its sides, as shown in Figures 3 to 5, with spring arms 38 having catches 3s adapted to be received under the flange 33 for holding the cover Sli and lightconcentrating box 3l in the lamp box lll. The ends of the spring arms 38 are provided with buttons @G extending through suitable openings in the cover Sli whereby the spring arms 38 may be pressed inwardly to release the catches 39 from under the ange 33 so that the cover Sil and the light-concentrating box Sl' may be removed.

The rear ofthe light-concentrating box 3l is provided with an opening 132 for receiving a concave reflecting mirror i3 which is carried by clamps #ifi in turn secured by a rivet l5 to a bracket llt. The bracket d6 is secured by screws i? to the light-concentrating box 3l' for holding the reflector d3 in the opening 42.

The light-concentrating box 3l is provided internally with a pair of concentric cylinders and 5l, the cylinder 50 being suitably secured to the cylinder 5i and the latter being secured by brackets 52 to the side walls of the light-concentrating box Sl. The inner cylinder 5@ terminates short of the reflector d3 and the outer cylinder 5l is provided with'openings 53 and 555 to permit the light generated by the lamp il to be reflected forwardly by the reflector 3. The opaque top l of the lamp ll', when taken in conjunction with the cylinders 59 and 5I and the latticed cover Si?, prevents light from escaping from the light box i4, While at the same time, providing free circulation of air through the lamp box E13 to dissipate the heat generated by the lamp Il.

Secured, as by welding, to the front of the light-concentrating box 3l are U-shaped brackets Stand 5l which provide supports for the filters and concentrating lenses. The bracket 51 is provided with a plurality of notches 58 of the same depth, and the bracket 55 is provided with a series of notches 5g, Se, GI, and 52 of varying depth. The bracket 5l and the front wall of the light-concentrating box 3l are provided with aligned holes 63.

The various notches are adapted to receive plates S5, $5, El, and 68 respectively. The plates are of varying height and, therefore, cooperate with the notches of varying depth to insure that plates 65, ES, 61, and 68 may be received only in notches 59, 60, 6l, and 62 respectively. The plates are provided with side flanges 69 to limit inward movement of the plates when they are insertedy in the notches, the flanges engaging the side of the brackets 58 and 5l. The plates are apertured and are provided with fingers '10 for securing the lters and the concentrating lenses in the plate apertures. Each of the-plates is also provided with a hole ll. As shown, the plates E5, E6, 6l, and B8 carry respectively in the apertures therein, a filter '12, a concentrating lens T3, a lter 14, and a concentrating lens l5. A pin 76 is adapted .to be inserted through the aligned holes 63 and H when the plates are properly received in the notches. The pin 16, therefore, retains the plates in position in the notches and the pin may be provided with a hook 'l1 engaging the bottom bracket 5l for maintaining the pin 'i6 in place.

By reason of this lter and concentrating'lens supporting arrangement, the lter and concenrating lenses may be readily removed and cleaned and may be readily repositionedin the projection machine. The lter and concentrating lenses may only be positioned in the projection machine in a predetermined sequence Whereby improper insertion thereof is prevented.

Referring now to Figures 2 and '7, the front of the lamp box I4 is provided with an opening Si) in alignment with the reflector i3 and the filters and concentrating lenses, and secured to the front of the lamp box I4 is a frame split'vertically in two parts Si and 82. The frame is also provided with an extension 83 for telescopingly receiving a tube Bil carrying the focusing lens 85. A friction roller 86 operated by aknob 8l is utilized for longitudinally adjusting the tubes Sli in the extension 83 for focusing the projection machine.

The frame, composed of parts 8| and 82, is provided with a horizontal opening, dened by surfaces 9E) of the frame which serve as a slide shifter support. This support is adapted toreceive a slide shifter @l carrying a shifting mechanism $2 operated by knobs 93. Slides may be inserted in the shifting mechanism 92, and by manipulating the knobs 93, the slides may be brought into alignment with the opening in the lamp box I4. When the slide shifter 9| is removed from the slide shifter support 9E), the side openings of the support 99 may be closed by a closure member 94, as illustrated in Figure 8. One side of the closure member 94 is enlarged, as at 95, to limit the movement thereof in the support 90, and the closure member 94 may be inserted or withdrawn by a knob 96. The purpose of the closure member Q4 is to prevent the passage of light through the side openings in the slide shifter support 90. The slide shifter 9| or the closure member 94 may be retained in the slide shifter support by means of a screw Sl. The slide shifter 9i and the slides operated thereby are contained in one transverse rplane between the source of light provided by the lamp il and the adjustable focusing lens 85. v

A lm guide 98, provided vwith a :light transmitting aperture 99, is also carried by the frame 8l. The front face of the film guide 98, having the aperture 99, is preferably curved, as illustrated in Figures 2, 14, and 15,'so that whenthe film to be projected is drawn thereover, it is prevented from curling due to the heat from the lamp Il. The film guide 98 is provided with lateral flanges, and one of these flanges carries 5. a pair .of pins received -in sleeves |0| carried between the frame parts 8| and 82, as shown in FigurelO. The other fiange of the film guide 98 is provided with holes |02 for receiving the sleevs -|0I. The pins |00 and the holes |02, therefore, support the vfilm guid V 98 and permit lateral movement thereof out of the path of light between the vconcentrating lenses yand the focusing lens. The nlm guide may be laterally moved by a suitable knob |03 carried thereby. In this way, the film guide with its relatively small aperture 99 maybe moved out of the way when slides are being projected.

The film guide 98 is in a dii-ferent transverse plane between the source of light and the focusing lens 85 than the slide support 90, and the location of the slides and the film in these different transverse planes may be readily compensated for by proper adjustment of the focusing lens 85 through rotation of the knob 81.

When it is desired to project from film, the lfilm guide 98 with its aperture 99 is placed in the path of light, the slide shifter 9| is removed, and the slide -shifter support 90 is closed by the closure member 94, as is illustrated in Figures l, 2, and 10. When, however, it is desired to project from slides, the closure member 94 is removed, the slide shifter 9| is inserted in the slide shifter support 90, and the lm guide 98 is moved out of the path of light, as is illustrated in Figures '1 and 9. This two-plane projection arrangement for films and slides therefore provides a simple means for alternately projecting films or slides without the necessity of dismantling the projection machine and converting it from a slide projector to a film f projector or vice-versa.

The film to be projected is drawn across the film guide 98 by a sprocket |05 Ahaving teeth engaging in the usual lm openings. As seen in Figure 10, the sprocket is carried by a shaft |01 having a key slot |08. A pin |09 in the sprocket |55 engages in the key slot |08 so that the sprocket |05 rotates with the shaft |01. One end of the shaft |01 is journaled in a boss |I0 on the frame part 82 and the other end of the shaft extends through a sleeve I| mounted in a boss II 2 on the frame part 8|.. The sleeve III is provided with a shoulder ||3 on one side of the boss I2 and carries on the other side of the boss a friction washer i I4 and a first part ||5 of a detent mechanism. This part ||5 is provided with cam surfaces I|6 and an extension |I1. A spring washer ||8 abuts the detent part ||5 and is held in place by a peened-over portion I|9 of the sleeve I I I at the end of the latter. The spring Washer H0 holds the first part ||5 of the detent vmechanism in engagement with the friction washer I|4 so that the detent part I5 is normally maintained stationary with respect to the frame 8|.

The detent mechanism includes a second part |2 I carried on the shaft |91, and this second part |2I is provided with a pair of studs |22 carrying cam followers or rollers |23. The rollers |23 engage the cam surfaces |I6 of the first part ||5 of the detent mechanism.

The end of the shaft |01 is squared, as indicated at |25, and this squared portion carries a knob |23 having a squared opening |21 engaging the end of the shaft. A screw |28 threaded into the end of the shaft |21 holds the knob |26 on the shaft. A Washer |29 also having a squared opening is carried adjacent the end of the shaft and abuts the inner surface of the knob |26. A spring |30 is vinterposed between the spring washer |29 and the second part |2.| .of the detent mechanism. The spring performs a double function of urging the rollers |23 into engagement with the cam surfaces ||6 and urging the knob |23 outwardly. The knob |25 is provided with an internal sleeve |3| provided with four grooves |32. Two of the grooves |32 receive the studs |22. I

The rollers |23 rest in the valleys between the cam surfaces IIB, thereby normally holding the shaft |01 and the sprocket |05 stationary and in predetermined positions. When the knob |26 is rotated, 1t rotates the shaft |01 and hence the sprocket |05 and it also rotates the second part |2| of the detent mechanism carrying the rollers |23 therewith. The rollers ride up the cam surfaces IIB from one valley and then fall into the next valley. The spring |39` permits the rollers |23 to be retracted by the cam surfaces I|6 as the shaft |01 and the sprocket |05 are moved from one predetermined position to the next. In this way, a detent mechanism is provided for moving the sprocket |05 to predetermined positions with respect to the frame 9|. The parts are so arranged that the movement of the mechanism from one detent position to the next corresponds to the movement of a single frame on the film to be projected. Thus the detent mechanism controlling the movement` of the sprocket |05 advances the iilm to be projected one frame at a time.

In order to line-up the frame of the film to be projected with the aperture 99 in the film guide 93, the knob |29 is, pressed inwardly against -the action of the spring |30 and one of the grooves |32 in the sleeve ISI formed in the knob |26 engages the extension I i1 of the first part ||5 of the detent mechanism. Upon rotation of the knob, the part ||5 is carried along so that the part IE5 is reset to the proper position in order to line up the lm with the aperture 99.

The film to be projected is fed to the film guide 98 and is maintained under tension along the film guide 98 by a hold back and reverse feed sprocket |35 having teeth |36 engaging in the usual openings in the film. One end ofA the sprocket '|35 is secured to a stub shaft |31 journaled in a boss |39 on the frame part 82. The inner end of the stub shaft |31 is provided with a slot |39. The other end of the sprocket |35 is rotatably mounted on a shaft |40 journaled in a boss MI formed on the frame part 8|. The shaft |40 is provided with a flange |42 which engages a friction washer |43 carried in the boss |4I. A spring washer |44 is interposed between. the frame part 0| and a knob |45 which is securely fastened to the shaft |40. The spring washer |44 urges the iiange |42 against the friction washer |43 to provide a friction brake for retarding the rotation of the shaft |40. The inner end of the shaft |40 is provided with a slot |46. A tension spring |41 is carried in the sprocket |35 and has its ends engaging in the slots |39 and |45. The iiange |42 is provided with a flattened surface |48 over which extends a pin |49 carried in the end of the sprocket |35. The flattened surface |48 provides a pair of spaced stops for the pin |49 whereby a lost motion connection is provided between the sprocket |35 and the shaft |40.

The torsion spring |41 biases the sprocket |35 and pin |49 to the rear, as viewed in Figures 10 and 11, so that when the film is drawn over the film guide, the sprocket |35 is first turned against the tension of the spring |41 and then the .pin |49 visibroughtinto engagement with the forward edge of the flattened surface |48, at which time the shaft |40 is caused to rotate against the action oflthe friction brake. The spring |41, there-- fore, holds back and maintains the lm on the lm guide in tension at all times, and as the film isadvanced, the shaft |40 is turned against the action of the friction brake. This placing of tension in the film while it is on the curved film guide prevents curling of the film due to the heat from the lamp |1. By manipulating the knob |45, the sprocket |55 may feed' the lm in the opposite direction along the film guide, thereby providing a reverse feed. The detent mechanism associated with the sprocket will maintain the film frames in alignment with the aperture 99 in the film guide 98 during the reverse feeding of the lm.

Located above the sprocket |35 is a container |55 for holding rolled film to be projected. The container is provided with a peripheral wall |56 and is closed on one side, but open on the other. The open side permits lateral placement of the rolled nlm in the container |55. A post |51 carried in the container may be utilized for carrying the rolled lm. The container |55 is secured to the frame by means of screws |53.

A pivoted arm |50 is utilized for holding the nlm against the sprocket |35. The pivoted arm |60 is provided with ears |5| pivoted to a shaft |62 which, in turn, is carried in the frame. A torsion spring |63 urges the pivoted arm |50 away from the sprocket 135, as is shown in Figure 14. The pivoted arm |50 is provided with slots |64 for accommodating the teeth |36 of the sprocket |35 and is also provided with a stop 65.

A pivoted lever |01 having a knob |58 is utilized for moving the pivoted arm |60 toward the sprocket |35 against the action of the torsion spring |63. In this connection, the pivoted lever |61 is provided with a crank arm portion |69 and is pivotally mounted in a bearing carried by the container |55.

Whenthe pivoted lever |61 is in the position shown in Figure 14, the pivoted arm'l60 is retracted by the spring |61 so that the film may be inserted in the container |55 and on the sprocket |35. After the film is in place, the lever |61 is moved from the position shown in Figure 14 to the position shown in Figure Where the portion |69 thereof engages the stop |65 and wherein the lever |51 is received in a catch |1|, shown in Figure 16, formed on the container |55. The lever |61 causes the pivoted arm |69 to hold the film against the sprocket and also extends across the open side of the container to prevent the rolled film from falling out of the container.

Located adjacent the sprocket |05 is a second pivoted arm |13 for holding the lm against the sprocket |05. r1`he pivoted arm |13 is provided with ears |14 pivoted on a shaft |15 carried by the frame. A torsion spring |16 biases the pivoted arm |13 away from the sprocket |65. The pivoted arm |13 is provided with slots |11 for accommodating the teeth |06 of the sprocket |95 and is also provided with a stop |18. A pivoted lever |19 having a knob |80 and a crank portion |8| is carried by a bearing |82 carried on a guide |83 having a peripheral guide portion |84. The guide |83 is secured to the frame by screws |85. The peripheral guide portion |85 guides the lm as it leaves the sprocket |05.

With the pivoted lever |19 in the position shown in Figure 14, the pivoted arm |13 is retracted by spring |16 so that the film may be placed over the sprocket |05. Whenthe pivoted lever |19 is moved to the position shown in Figure l5, the pivoted arm is moved toward the sprocket |05 against the action of the spring |15 to hold the film on the sprocket |05. As will be noted in Figure 15, the pivoted lever `|19 is substantially normal to the pivoted arm |13 so that the spring |16 hasno tendency to swing the pivoted lever. |19 from the position shown in Figure 15. In this way, the parts are locked in the Figure 15 position. When, however, the lever |19 is moved out of the Figure 15 position toward the Figure 14 position, the spring |16 urges and retains the parts in the position shown in Figure 14.

The pivoted arms |60 and |13 and the pivoted levers |61 and |19 provide a simple mechanism for maintaining the film against the sprockets |35 and |05, but still permit ready insertion and removal of the film. In addition, the pivoted lever |61 provides the further function of maintaining the rolled film in the container |55.

Generally speaking, the claims of this application are directed to the two-plane feature for projecting slides or film, to the friction brake feature, to the reverse feeding feature, and to various combinations thereof. Claims directed to other disclosed features are contained in the copendng application of Thomas I. Ress, Serial No. 700,087, filed September 28, 1946.

While for purposes of illustration one form of this invention has been disclosed, other forms thereof may become apparent to those skilled in the art upon reference to this disclosure, and, therefore, this invention is to be limited only by the scope of the appended claims,

What is claimed is:

l. In a projection machine comprising a light source, a supporting member having an aperture, and a converging and a focusing lens respectively arranged in axial alignment with each other and with the aperture on opposite sides of the supporting member; a lm guide arranged between the aperture and the focusing lens and having a light opening, means mounting said lm guide on the supporting member for lateral movement between positions respectively wherein the light opening is disposed coaxial with the aperture and lenses and wherein the film guide is withdrawn from the path of a light beam passing from the converging to the focusing lens 'through the aperture, and slide supporting surfaces on the supporting member between its said aperture and the converging lens.

2. In a projection machine comprising a light source and axially spaced and aligned rearward converging and forward focusing lenses; a supporting member interposed between said converging and focusing lenses and comprising a body extended across the path of a light beam passing from the converging to the focusing lens, said body having a light passage therethrough comprising an aperture extended rearward from the front surface of the body a limited distance-in coaxial relation to the lenses and a slide chamber in said body in the rear of said aperture and opening through the rear surface of said body, a film guide spaced forward from the aperture toward the focusing lens and having a light opening, and means mounting the film guide on the supporting member for lateral movement between positions respectively wherein the light opening is coaxial with the aperture and lenses and wherein the film guide is withdrawn from Ythe path of a light beam passing from the converging to the focusing lens through the aperture, surfaces of the body bounding the slide chamber providing means for supporting a slide in registration with the aperture.

3. In a projection machine comprising a light source and axially spaced and aligned rearward converging and forward focusing lenses; a supporting structure interposed between the converging and focusing lenses including a body extended across the path of a light beam passing from the converging to the focusing lens and having therethrough an opening providing a light passage for such a beam, said body having parts extended forward at opposite sides of the path of such a light beam, a film guide extended across the forward surfaces of said parts and having an aperture, a flange on said guide extended rearwardly between said parts, and a rod extended transversely between said parts and slidably penetrating said flange whereby said film guide may be slid upon said rod from a position extended across said light path and with its aperture coaxial therewith to a position outside said light path.

4. In a projection machine comprising a light source and axially spaced and aligned rearward converging and forward focusing lenses; a supporting structure interposed between the converging and focusing lenses including a body extended across the path of a light beam passing from the converging to the focusing lens and having therethrough an opening providing a light passage for such a beam, said body having parts extended forward at opposite sides of the path of such a light beam, a lm guide extended 10 across the forward surfaces of said parts and having an aperture, a flange on said guide extended rearwardly between said parts, a rod extended transversely between said parts and slidably penetrating said flange whereby said lm guide may be slid upon said rod from a position extended across the said light path and with its aperture coaxial therewith to a position outside said light path, and sprockets mounted between 'said forwardly extended parts of the supporting structure above and below the lm guide for alignment with said guide when in the first of its said positions.

ARTHUR J. BRADFORD.

REFERENCES CITED The following references are of record in the file of this patent:

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